1. Field of Invention
The present invention relates to rigid foam insulation panels and, more particularly, to a method and apparatus for cutting such rigid foam insulation panels.
Rigid foam insulation panels are widely used in the building trade to provide an additional layer of insulation in the construction of new homes and commercial buildings. Typically, such rigid foam panels are used as a replacement for fiberglass batting and are cut to fit between wall studs. Sheets of rigid foam are also installed on the sides of houses being constructed, remodeled or repaired to provide additional insulation to the exterior walls. Such foam panels provide good thermal resistance and often add structural strength to the building. Since such rigid foam insulation panels are well known to those skilled in the art further detailed discussion of the same is not deemed necessary.
A problem is encountered in cutting rigid foam insulation panels on the construction site. Such foam panels are typically provided in four-by-eight foot sheets and are often cut manually by the use of a utility knife and a straight edge. Using this method the foam panel is partially cut to a limited depth at the desired dimension and, thereafter, manually snapped along the superficial cut. However, this technique produces an uneven cut surface and quickly dulls the utility knife blade after repeated use resulting in damage to the foil moisture barrier which is typically adhered to the surface of the foam panel.
Alternatively, circular saw or a table saw powered by an electric motor is utilized to cut the rigid foam panels, but this technique produces a substantial amount of airborne foam insulation particulates, which pose a health hazard to the user or to anyone in the vicinity.
2. Background Art
There are prior art patents that are available in the field of the present invention and their discussion follows. One method for cutting rigid foam panels employed in the past has involved the use of electrically heated wires which are drawn through the foam material to cause severing of the cellular material. For example, U.S. Pat. No. 3,786,701 discloses a Device for Cutting Urethane Foam comprising a carriage adapted to advance a slab of urethane material through a cutter assembly including groups of elongated cutting wires which are heated and oscillated longitudinally to clean the wires as the material is advanced through the device. However, the melted foam material inevitably builds up on the hot cutting wires preventing a satisfactory cut of the foam material. The oscillatory drive mechanism is powered by a conventional drive transmission means such as a belt and pulley arrangement connected to a drive motor, which has all the electromechanical complexities of such a powered system and the related maintenance problems as well.
Another method of producing boards of cellular material involves the use of blade cutting equipment. For example, U.S. Pat. No. 3,242,779 discloses a Reciprocal Saw for Cellular Resinous Bodies which is a multiple blade machine capable of sawing a foam block into a plurality of boards during a single pass of the machine. Generally, such a reciprocal saw apparatus involves a number of problems including the ability to change blades and blade settings readily and the maintenance of a conventional motor and drive mechanism.
Thus, the present invention has been developed to resolve these problems and other shortcomings of the prior art.